A large angular-fitting stone, that had been for ages, with its lower flat side, a smooth and polished portion of the ceiling of the inclined and narrow entrance-passage, quite undistinguishable from any other part of the whole of its line, had now dropped on to the floor before their eyes, and revealed that there was just behind it the end of another passage, clearly ascending therefrom towards the south. That ascending passage itself was still closed a little further up by a portcullis or stopper, formed by a series of huge granite plugs, of square wedge-like shape, dropped or slid down, and then jammed in immovably from above. To break this in pieces within the confined space, and pull out the fragments there, was entirely out of the question; so the workmen broke through the smaller ordinary masonry, and thus up again by a huge chasm—still visible, and used by visitors into the interior—to the ascending passage, at a point past the terrific hardness of its lower granite obstruction. They found up there beyond the portcullis the passage-way still blocked, but the filling material at that part was only limestone; so, making themselves a very great hole in the masonry along the western side, they there wielded their tools on the long blocks which presented themselves to their view. But as fast as they broke up and pulled out the pieces of one of the blocks in this ascending passage, other blocks, also of such a size as to completely fill it, slid down from above, and where there should have been free passage there was still an obstruction of solid stone. The men despair; but the Caliph, being present, insists that, whatever the number of stone plugs still to come down from the mysterious reservoir, his men shall hammer and hammer them, one after the other, and bit by bit, to little pieces, at the only opening where they can get at them, until they at last come to the end. So the work goes on, till at length the ascending passage, beginning just above the granite portcullis, leading thence upward and to the south, becomes free from obstruction. On they rush, up one hundred and ten feet of the steep incline, crouching hands and knees and chin together, through a passage of polished white limestone, forty-seven inches in height and forty-one in breadth. They suddenly emerge into a long high gallery, all black as night and in death-like silence; still ascending, they see another low passage. On their right hand is the dark, ominous-looking mouth of a deep well, in which not even at a depth of more than 140 feet is the water reached; while onwards and above them is a continuation of the gallery leading them on.